A recurrent topic in the financial press for much of 2018 has been the rising risks in the emerging market asset class. Emerging economies are, of course, a very diverse group. But the yields on their sovereign bonds have climbed markedly, as capital inflows to these markets have dwindled amid a general perception of deteriorating conditions.

Historically, there has been a tight positive relationship between high-yield US corporate debt instruments and high-yield EM sovereigns. In effect, high-yield US corporate debt is the emerging market that exists within the US economy (let’s call it USEM debt). In the course of this year, however, their paths have diverged. Notably, US corporate yields have failed to rise in tandem with their EM counterparts.